Heat-treating container



2 SHEETSSHEET l N. L OLSON HEAT TREATING CONTAINER- FILED MAY 19 1921 ATTORNEYS 2 SHEETS SHEET 2 Feb. 6, 3923a N. L. OLSON. HEAT TREATING CONTAINER FILED MAY 19. 1921 INVENTOR. ]\/e/sl.0/$0 BY ATTO EYS Patented ll 6, i923. 9

NELS L. OLSON, OF DETROIT, MICHIGAN.

HEAT-TREATING CONTAINER.

Application filed May 19, 1921. Serial No. 470,928.

To aZZw wmz't may concern: covers on top. it is readily understood that Be it known that I, hints L. Orson, a citithe boxes are closer together at the top than zen of the United States of America, residthey are at the bottom, and in order to fill ing at Detroit, in the county of Wayne and the furnace to capacity it is necessary to State of Michigan, have invented cer have them come in contact with one another 430 tain new and useful Improvements in Heat at the top. This has a tendency to localize Treating Containers, of which the following the heat at the upper parts of the boxes and is a specification, reference being had therethis is shown in practice by the fact thsjt the in to the accompanying drawings. boxes oxidize or scale off at the top much 10 This invention relates to the equipment faster than at the bottom; many boxes with 65 used for the heat treatment of steel such as still serviceable bottoms are scrapped beis necessary for the improvement of vmany cause the upper parts are burnt 0%.

steel parts produced for the automotive in- One of the objects of my invention" is to dustrles, and particularly to containers used provlde a box or container so constructed l onlz ng op rat that heat cannot alter its shape when used 70 The common practice is to pack the steel for heat treating purposes. Another object parts to be carbonized in a metal box with of my invention is to obviate the necessity of case-hardening material. Each box being using the clay or similar material to proopened at the top, a cover is laid on it and duce a seal between the box and lid.

a seal made by means of wet fire clay in- A further object of my invention is to 75 serted between the box and cover. The box provide carbonizing boxes or containers of or boxes are then placed in a heating furnovel shape and by which a method of arnace and brought up to the required temperranging the boxes and containers of a furature. Under such conditions, carbonic nace may be carried into efiect to insure unioxide gas is generated and the surface of the form passages between the boxes within the steel to be treated, being red hot, absorbs carfurnace. bon from the gas thus producing on the steel A further object of my invention is to proparts a carbonized case capable of respondvide a heat treating box with openings ing to ordinary hardening and tempering whose combined area is less than the cross Operations. sectional area of the box, thus affording The seal between the box and cover must gussets at the corners of the box for lendbe perfect, otherwise the gas escapes from lng rigidity to the walls thereof against the box and no carbonizing takes place. warping when subjected to heat within a The fire clay seal is not satisfactory, for furnace.

the reason that clay shrinks and cracks The above and other objects are attained under the heat and allows some of the gas by boxes or containers of various forms,

to escape. Furthermore, another difficulty some of which are shown in the drawings encountered is that after repeated heatings whereinand cooling-offs the b0); loses its original Figure 1 is a plan of an ordinary box ex- 40 shape, warps and cracks and makes it intensively used in heat treating plants, showcreasingly dificult to maintain a tight joint. mg by dash lines how the walls thereof The carbonizing boxes being cast, it is Warp; necessary in order to remove the pattern Fig. 2 is a plan of a box embodying mv used in their manufacture from the sand invention;

i5 mold, to give theseboxes a tapered shape, 3 is longitudinal sectional view or that is, to make them a little smaller at the the same with lids in proximity thereto;

bottom than they are at the top. Now, when Fig. i is an end view of a box; the battery of boxes are inserted in a fur- Fig. 5 is a plan of a small box; nace, it is desirable to place them as close as Fig. 6 is longitudinal sectional view or" 50 possible to one another in order to take adthe same, showing the lid in proximity vantage of the full capacity of the furnace thereto; and at the same time to allow enough space Fig. 7 is a longitudinal sectional view of between the boxes for the heating gases to a modified form of box with a lid in pron travel. Due to the tapered shape of the conimity thereto;

55 tainers, when they are arranged with all the Fig. 8 is a bottom plan view of the same; 11 if;

Fig. 9 is an end view of a box.

Fig. 10 is a plan of a lid that may be used in connection with my boxes;

Fig. 11 a side elevation of the same;

Fig. 12 is a plan of a battery of boxes;

Fig. 13 a side elevation of the same.

In order that the purpose of my invention may be more clearly understood, 1 have shown in Fig. 1 an oblong box 1 and the side walls 2 of this box have been warped or bulged, as indicated by dash lines, due to the extensive use in a furnace wherein the box has'been subjected to heat to carbonize the contents of the box. As pointed out in the beginning, such a box is closed by a lid and sealed by use of fire clay, and it is obvious that when the walls are warped, cracked or other than their original shape and condition, that it is practically impossible to fit lids on such boxes and thoroughly seal the same.

To prevent warping and bulging of the box or container walls, I make a box 3 with a top wall 4 provided with one or more circular lid openings 5 and that part of the wall 4, which is not cut away, provides gussets and webs which re-inforce and stiffen the walls of the box or container, particularly at the corners of the box. The box which has two openings, as shown in Fig. 2, has a central web portion which constitutes a tie or brace between the sides walls of a box.

. The bottom of the box 3 has a plurality of legs 6 and said box is adapted to have its openings 5 closed by lids 7, said lids having the peripheral edges thereof beveled or tapered and adapted to snugly wedge or fit in the openings 5. The walls of the openings 5 can be machined to insure a perfect lid fit and should the lids stick or bind within the openings 5, tapping on the lid will tend to loosen the same. To facilitate removal of the lids, I may provide the same with lugs 8 projecting outwardly from said lids and overhanging the top wall 4 of the box or container, and if the lids can not be removed by tapping the lugs with a hammer, a crowbar can be inserted between the top wall 4: and said lugs and the cover pried off without difficulty.

In Figs. 7, 8, and 9, I show a box 9 having an end opening 10 adapted to be closed by a lid 11 and this box has been especially designed for carbonizing long parts, as cam and crank shafts, which may be placed in the box when on end. This box also has feet 12 to maintain the box in spaced relationto the bottom of a furnace.

Considering the battery of boxes shown in Figs. 12 and 13, each box has side walls 13 tapering inwardly from the top of the box to the bottom thereof and the bottom of the box has legs 14, while the top thereof has a circular opening 15 adapted to be closed by a lid 16, somewhat similar to the lid shown in Figs. 10 and 11. The lugs on the lid 16 will serve as feet, when the box is inverted and it will be noted that alternate boxes can be placed in such inverted positions so that there will be uniform passages 17 between the boxes and under the bottoms thereof. Such spaces will even exist if the boxes are placed in superposed relation and by leaving a uniform space about all of the boxes there can be a thorough circulation of the heating gases, which insures a uniform heat and prevents one part of a box being heated to a greater extent than another. The arrangement of the boxes also contributes to a full capacity furnace, and by reversing tion of the boxes, from one heat to there will be a uniform wear and length of service for the boxes.

It is obvious that when a box is inverted that the weight of the same insures a seal sufficient to retain carbonizing gases within the box, and I attach considerable importance to the configuration of the boxes which permits of compact arrangement of the same within a furnace.

What I claim is 1. Heat treating containers for carbonizing parts sealed in said containers and another, greater wi'ierein the containers are subjected to heat within a furnace, said containers having side walls tapered inwardly from the upper ends of said containers to the lower ends thereof which permits of inverted containers co operating with upright containers in providing uniform passages between side Walls of adjacent containers when arranged. in laterally extending rows. r

2. Heat treating containers for carbonizing parts sealed in said containers and wherein the containers are subjected to heat within a furnace, said containers having a configuration which permits of inverted containers cooperating with upright containers in providing uniform passages about adjacent containers, and lids for the containers having lugs serving as feet for the inverted containers.

3. As a new article of manufacture, a heat treating container tapered from top to bottom, legs on the bottom of the container, and a lid for the top of the container, said lid havinglugs serving as feet when the container is inverted.

i. As a new article of manufacture, a substantially rectangular heat treating container having an opening affording gussets at the side walls of said container, and a lid closing and sealing said container by frictionally engaging walls of the container opening.

As a new article of manufacture, a heat treating container, a lid therefor, and means carried by said lid serving as supports for said container when inverted and the posia heat treating container, consisting in snugly fitting the lid in the container, and then inverting the container so that the Weight thereof is borne by the lid.

In testimony whereof I aflix my signature 15 in presence of two witnesses.

NELS L. OLSON. Witnesses ANNA M. Donn, KARL H. BUTLER. 

